利用

We should do down of the exceptional opportunities open in exports.

我们应当好好利用出口方面现成的难得良机。

欺骗

He did the old lady down into lending him all her money for his business.

他哄骗了老太太把所有的钱都借给他做生意。

击倒，击败，使遭到不幸

Perhaps they will be unemployed ，or otherwise done down.

他们可能会失业或遭到其他不幸。

说(某人的)坏话

The student often does down his fellow students.

那学生经常说同学的坏话。

使(自己)感到羞愧

There's no need to do yourself down.

你不必感到羞愧。